Measured-service system for telephone-lines.



PATENTED OCT. 29.1907.

J. L. MGQUARRIE. MEASURED SERVICE SYSTEM FOR TELEPHONE LINES.

APPLICATION FILED T113723. 1906.

qu 'fi INVENTOR wmvsssus:

UNITED STATES JAMES L. MCQUARRIE, OF O.-\ K PARK, ILLINOIS, ASSIGXOR TO WESTERN ELECTRIC COMPANY,

OF CHICAGO, ILLINOIS, A (ORPORATION OF ILLINOIS.

MEASURED-SERVICE SYSTEM 1 03 TELEPHONE-LINES.

Specification of Letters Patent.

Patented Oct. 29, 1907.

Application filed February 23. 1905- Serial No. 302.493.

To nil whom it may conzrrn:

lie it known that. I, Janus L. MCQIARRH-I. a citizen of the United States, residing-at Oak Park. in the r-utttll y of (look and State of Illinois, have invented certain new and useful Improvements in Measttrod-Service Systems [or 'lelephonc-Linos, of wltich the following is a specilication.

l y invention relates to the measurement of telephonic service, and has more particularly to do Willi the selective registration of telephonic calls originating in any one of a ntttnber ot subscribers stations connected with and served by a single telephone line.

here charges for telephonic service are based upon the number of calls made by a subscriber, and several subscribers stations are served by the same telephone line, it becomes necessary, in order correctly to apportion the charges among the various subscribers. to provide for as ertaining at which one of the several stations of the line each call originates, so that it may be entered npor charged against that station: and, when the identity of the calling station has been determined, it is desirable to provide suitable registering mechanism associated with the line for enabling the calls of the ditlerent stations to be separately recorded and totaled.

In the system of a prior patent, 766,192, issued to me August 2. 190-1, these requirements are met by associut ing a connection register for each station with the line at: the central ollice. and providing menus at each station for automatically determining the operation of the re ister corresponding with that station in the act of intt iat inge. call, the regist rat ion being effect ed by means :m ociated with the cord circuit through the agency of which the call is answered. Such a systenrhas the advantage of insuring against the 'call being charged to the wrong station through the error of the operator or through the subscriber misint'orming her as to his identity, and. it is to a system having these general characteristits and advantageous features that the invention of my present application relates.

in :tt't'ttl'tlttlltt) with the embodiment. of my invent ion herein described and illustrated I determine the selection and operative connect ion with the line of the connection register at the central oflice corresponding with a particular substation, by means'ot' a current controlling device included in the bridge of the line at one of the'substatioes which includes the telephone and is controlled by the-telephone switch hook. The current controlling device which I prefer to employ is a high resistance, or like current reducing means. which. by its inclusion in the telephone bridgtu reduces the current flow in the line when the telephone is taken for use to the point where it is insutlicient to actuate register selecting mechanism provided at the central otlice,

while suflicient to display the calling signal, the nonoperation of the selecting mechanism leaving the register mrresponding with the calling station in operative relation with the line: while the current when the other station calls is adapted to be sutlicicnt to operate the selecting mechanism, as well as the calling signal, and

thus serve to disconnect the first register and operatively associate another register with the line.

.To prevent the cun'e! reducing device included in the telephone bridge at the substation trout interfering with eilicient telephonic transmission, I prefer to associate with it mechanism which operates, after the device has performed its function, to neutralize it, or remove it from the telephonic cir uit.

In'ill describe my invention more particularly by reference to the accompanying drawing, which is a dit gmmmatic representation of a telephone line equipped insec -"lance with my invention extending him two stations toa central otliee, and there adapted t'orconnection with another telephone line through the medium of a connecting cord circuit.

As illustrated, the telephone line may extend in two limbs 1, 2 from two stations A, B to the central office 0 where it is connected with the spring jacks or connection terminals c, and has a normally closed extension through he conlacts of a cut-off relay dto the poles of a. central batt ry 5, the winding of a zline relay 0 and one winding of a selecting relayf beingliucluded in the oxten ion of limb 1. One of the poles of the central battery. in the present instance that. as )ciated with limb 2 of the line, may be connected with earth or a return conductor, in accordance with the usual practice.

I have shown a number of batteries marked 5 asse ciated with different parts of the circuit, for convenience of illustration; but it will be understood that these may be, and in practice ordinarily are, one and the some battery.

As ociated with the line at the central office are a number of connection registers which may correspond in number with the stations connected with the line. In he prtsent instance two designated 9 and h are shown, one for station A-and one .for station B. The

reprtscntatiun of the connectionregisters herein is' merely a diagrammatic one, the registers shown being of a type familiar in the art, andc'omprising an electromagnet adapted to effect the advance of a counting 1min, indicated at g and h, by means oi slep -by-step mechanism operated by the armature of magnet. In

the type shown in the present instance, the magnet of each register is provided with two windings g, g Ind it, IE, res x-ctively, the windings g" and It being adapted to effect the primary actuation of the registers, while windings g, It", respectively, are closed in contacts 9 IF when the registers are actuated to retain the register mechanism in its operated position.

t i t t a The circuit by means of which the connection registers g, and h are actuated is associated with the connection terminals t of the line, and in the present instance is a branch 11 of conductor 10 which is connect cd to the test sleeves or tbimbles of the jacks and extends to earth through the winding of cut-off relay (1. (onductor 11 has two branches l2 and I3 in which the windirigs g and h, respectively, of the two connection registers g and h are included the twobrancln-s being adapted to be closedalternatively in the switch contacts f of the selecting relay f. Branch 12 including the winding of connection register 9 is normally completed in the resting switch conta ts of relay f, and is therefore in operative relation with the connection ter= minals of the line. When-the armature of relay f is attracted branch 12 is interrupted and branch 13 containing the winding of connection register it is completed instead, a part of the current which may be flowing in conductor 11 being diverted to earth through conductor 14, which includes a winding/ of the relayf, thus serving to maintain the relay actuated and the circuit of branch 13 closed so long as current is supplied through i traversed by currpnt flowing in the line. The windmentof the arniatures.

ings are so proportioned, however, to the parts that they are adapted to energize that a predetermined flow of current will cause both to actuate their associated mechanism, while less than the predetermined flow will cause the operation of the line relay but fail to operate the selecting relay. This result may be effected in any convenient manner, as by varying the turns and resistance of the winding, or by regulating the adjust- I also find it convenient to make the selecting relay f of a type that is rendered sluggish in its response to the energizing current, as by providing an armature of relatively large mass pivoted before the magnet in a peculiar way, as shown. This is to prevent the response of the relay to momentary impulses of current caused by accidental closures of the circuit in the course of making connection.

A line signal, shown in the present instance as a miniature incandescent lamp, 1 is associated with the answering jack of the line, in accordance with the usual practice, and is included in a conductor extending between the poles of the central battery i and controlled in a normally open contact of line relay e. The connection of the line relay with the line, and consequently the illumination of lamp 1, is controlled in contacts of the usual cut-off relay d included in conductor 10 connected with the test sleeves of the connection terminal c.

.circuits and apparatus which causes a different elcc.

trialcondition of the line circuit when substation I 'allsfrorn that when substation A calls.

As has heretofore been stated, the winding and the moving parts of relay f are so adjusted that the circuit is actuated only by current flow of a predetermined value in the line circuit any flow less than the predetermined a mount. not affect ing thereby. I therefore, in order to cause rclayf automatically to distinguish between the stations calling, provide an organization at substation it which serves to reduce below the predetermined value the current flowing in the line when the telephone at that station is taken f r use; while, no such provision being made at substation A, the act of taking the telephone for use at that station creates a condition of normal curren flow in the line which is so regulated as to be sufficient to actuate relayf The equipment at substation A comprises the usual gether with a bell in a branch from limb l of the linef and in addition comprises the current. reducing apparatus which will be particularly described. This, in the present instance. consists of a relay it having a low resistance winding a and a high resistance winding a", together with a resistance coil 1) interposed in the bridge 7 of the line with the telephone apparatus heretofore mentioned. The resistance of the winding a" may conveniently be 12 ohms (preferably shunted with a non-inductive resistance of 100 ohms,not shown), the winding 11' may have a resistance of 1000 ohms, and the resistance of the coil 1; may be 2500 ohms. The relay lias normally separated contact members a which control a conduc or 8 adapted to complete a short circuit about the high resistance winding 11 and the resistance coil b when the relay is energized, the low resistance winding 11 being allowed to remain in circuit in order to maintain the energization of the relay. As is indicated diagrammatically, the relay a is preferably polarized in order that it may be responsive only to current flowing in a certain direction in the line, so that it may more conveniently be controlled from the central ofiice. I

The line with which I have assumed the line extending from substations A B is to be connected, extends from substations D E in two limbs 5 and 6 to connection terminals r and theusual line signal apparatus at the central otlice. The line signal apparatus is represented in the present instance as comprising a. line relay e controlling a line signal or lampl, and controlled in turn by the usual cut-off relay 11'. Current for the actuation of the relay and the signal is derived from the central battery The telephone lines are adapted to be connected together, in the present instance, by a connecting cord circuit terminating in an answering plug 0 and 1 calling plug 0 arranged for insertion in the connection terminals of the two lines. The connecting circuit proper extends in two conductors 3 and 4 between the tip and ring contacts, respectively, of the plugs o o, windings m m and m m of a repeating coil or being preferably included in the conductors 3 and 4, res urtively. while between the windings of the repeat. lug coil is a bridge of the. circuit including aerator battery i.

It will be med that the line circuit 1 2 and the connecting cord circuit 3 4 are so arranged that the direction of the current flow in the line will be reversed 35 the sleeve or body oi answering plug and thence hy 'limh 1 of the line is normally connected with the nemtive or free pole of the central battery and liiuo 33 is connected with the positive pole or (-arthcd pole. uhen plug 0 is inserted in one of the jacks oi the line, lirnh l comes into connection with the positive pole. while limb 2 is connected to the negative pole. This is for the purpo e of bringing about the actuation oi the polarized relay 1: at substation ll to short circuit its high resistance winding and the resistance coil b when connection is made with the litre.

The connecting cord .circuit is equipped in the usual manner with a listening key -n in! cit-aiding rlu operator to bring her telephone apparatus into association with the circuit, and with ringing keys n n'-' Al'l'llllgvtl lo apply current from generator 1 to one or the other oi the limbs of the line to ring selectively either the slation D or station E. The circuit is :tlz'o proridcd with supervisory relays k 1: connected in the answering hali and the calling half. respectively, oi the cord circuit. and controlling supervisory signals or huups l- I. Trspectively, through the medium oi resistances j jincluded in the signal strands l6 and 17 respectively of 23 the answering and calling cords.

To enable the epemtor to actuate the particular coirnection register which is autonraticully sele ted and brought into operative relation with the line by means of the apparatus heretofore descrihed. I provide actusting means associated with the cord circuit. comprising in the present instance. a suitahle sourceoi cur ent. ladapted when applied thereto to energize the connection registers and a switch or key 3 for applying current. irom the source 1 through the tncdirini oi (t-Iulllclui' IS in way of the sleeve or thiruhle oi the jack and its associated conductors to one or the other oi the rcgist crs. I In accordance with well known pmct ice 1 include in conductor 18 an elcctro-nnrgnctic service ureter r. com- 40 mon to all the cords in the operator's position. to regi ter the total of all the separate registrations which may he made by the individual registers oi Ihe lincsterrninating on that position: and associate therewith a. pilot lamp 1 having its actuating circuit l9 completed to current which rlows ironr the battery [to the hody oi the plug o by way of the thinl stnrnd it; or the answering cord and theme tocondnctors l0 and ll and either I: or 13 when the answering plug is inserted in one oi the jacks r while suilicient to bring about the actuation oi cut-oll' relay I], and to maintain rclzcvfoperzrtdd when the circuit through its locking wi riding is once closed. is insuilicient. oi itseli to actuate the connect ion register 9 orh to which it is applied. llut when current'irmu the source I is applied to the syst m of conductors lr the operation of switch or key a or when llrc current is inlion. n l 45 light the lump upontheopemtron ol the register r. the r dtnnrrly is made.

i The upct'ntion oi the system oi my it:\'cniotr is as loli lows: As ume that the suh crihe at station wishes to he put in conunuuicatirur with the snhscriheral lnliult 1).. lielirsl takes his telephone inuu its hook. which completes rlrecircuit oi the ine !l rnlt 'lt hrizlgc J to per- 40 mil current to How l'r-uu the central lliilitl'h h w-.r of the xz'n l og oi the line relay: :rnd the wrndiugj" oi the selecting ictsrf. This actunles the line relay to close the circuit nun eil'ccl the ill. 'iuotiou oi litre lamp I. and, the resistance interposed by the lntnsmitter :rud induction coil to the lion oi current through the bridge it ill the sulistation heiiu! slight suilicicnt current lion's over the cirr oil of the lime lo'caus the actuation oi relzryf. \\'hcn tlrc rcluyf utrzrcts its -.utn:rturc normally closed brain h 12 through tht windingoiconnection rcgis: er 1 is interrupted. and ln'ztnclr lil through onnection register it is closed in its stead. while at the some time .lmrnch H containing the locking winding f-' oi relay f is ht'onghl into operative conuectio'r with the test sleeves oi the jacks c. $5 the illutnirnuiou oi lamp I. inserts thc an wering pint: o

The operator upon oh erru oi the p.rir oi cords into the :t 'sut'inittl jack. thus extending conductors l L! oi the line to conductors I! -l oi l the cord circuit. and a: the same time cousin; current I iron] tlrcccmrnl battery fro ll w l) way of conduct r it:

oi the cord circuit to the tes slcere oi the jack in which the pln; is insert d. and them e h wuy oi the cowl-1ctors H). II. II nnd ii to the culol'i relay J, the lochin; winding f oi the selecting l"'in f and the winding h oi the onncctiou re stcr It. The cut-oil relay is thereupon actua ed to disconnect the normal extension oi the line through the line lt-l.r nud selecting rc y to the central lmttr-rr. while the locking winding/ ot the Selecting l'cl:r

is energized to keep the armature oi that rclay from killing lr..t'l;. now that hrilow oi cur- IOU t'c-ni thr ugh wiudingf has been interrupted. puriion oi the current iiows through winding of connection l't istcrlt but .as has lit-en lrerclol'orc stat d. this is insuilicrcirt t cause the register to opera e, \r'hcn the operator. lr means of her lisit'lrillg l;c n has learned that lllt'fililis'tl'ilvt'l\\i$l|0sr't-llht-t'lil ll with sltlr tntiott i 'she depressesringing ltc n". which upphcs ringing currents Iii liruhz'i oi the line to ring: llohell at that suhsorll the rulrseriher does not respond no charge or- H lit-docs respond however. and communiculion with the calling' uhscriln-r is had the opt-intuiregisters :1 charge against the cnllin; snhscrilier l) depressing switch or key x :rssncintcd with the counecliug cord 'llredepres iouoi this hcyconrph-tcs the l'il't'llll cxteudiu; irorn llu sourccol' current I to the connection egister II. mores-pivudin; with sill-stution lr war oi conductor l8. the hotly oi the answerin; plugnu l the slcc\'c oi thejnch in which it is iuscried. conductors lit and H. the alternative t'tntlzlcl oi selecting rchryj' illlll t'ulltllh'lcl' l3. ilnt urreu; also passing through llrc winding oi the operator's register r.

creased to the requisite amount in any other manner: 'whichevcr connection register is in connection with i conductor-a ll; ltlund ll iszrclnnted. and. upon l-eingnc- 50 "rated. closes ilscircuil g'-'or l asthecnsenrzryhe thus The current which is thus caused to How is such a :o actuate '"llllt'l tiou register II. the regi ter lit-ill: maintained in its opclntel osition during;- the rest oi the time that the plug remains in the jack lay the nctiutr of locking itself in its actuated position. At the some locking winding Ic', 'ilucurrent tlow that actuates time the flow oi current from source I act nah-s durrrtl register Ii zlso rnltsc-= the operation oi the operator's l'cgmot: register which. in turn. closes the circuit oi and raring hritws rllk tll the illtuuiunilluminates pilot hunp I. thus indicating to the opertion oi ramp 1. and thus indi ates to the operator that 55 alor that the registration has been made.

i the call lrns been recorded.

,\upe.rri. ion oi the counccr i i.

connection with such lines.

tion is had in the usual manner through the medium of supervisory lumps l and I and when the connection is taken down all the apparatus is restored to its normal condition.

5 When the call is from substation B, the subscriber in taking his telephone from its hook completes the bridge 7 of the line, whic' howevcgin this case, includcs in addition to the transmitt r and induction coil, the windings of relay (1 and the resistance coil I),

10 the resistance thus interposed to the passage. of current from the battery reducing it to less than the amount required for'the actuation of selecting relay 'f. The result is that while line relay 6, which is more sensitive, is actuated to cause the display oiline signal t, relay}:

is not operated to switch its locking winding f, and the register h into connection with the spring jacks oi the'line. Instead the normal connection oi rcgsiter g with the test sleeves oi the jacks is uninterrupted, so that when the operator responds to the line signal by inserting the answering plug of the pair oi cords into the answering jack of the line. selecting elay f is disconnected, and register g left in position to he operated by an application of actuating current from generator t to the sleeve of the jack, in the manner described in connection with the call originating in substation A.

The office of the high resistance included in bridge 7 in: substation B ends with the prevention of the operation of selecting relay f, and after connection is rimde with the line it is desirable that resistance be removed 80 or neutralized in order to prevent it from interfering with theproper transmission of telephonic currents, and the proper supply of current for the operation of the substation transmitter. This is effected in the present instance, as has hereiubeiore been described,

by employing the polarized relay a adapted to respond only to current flowing in one direction, and organizing the. circuits at the central-other,- to cause a reversal in the direction of current flow when connect on is made with the line. The consequence is that when the operator, in responding to the line signal I, inserts the answering plug 0 into jack c, relay a is actuated, and, in closing its contacts; completes conductor 8, which short circuits high resistance winding 0'' null resistance coil b. only low resistance winding (i r main.

ing in circuit. to maintain the cnergization oi the relay. The same action takes place. whether it be an answering plug or a calling plug that is inserted into a jack of the line,u.nd consequently the high resistance at substation b is operative only when it is required in initiating a call to control the actuation f selecting relay 1, and is thereafter removed from the circuit.

Although particularly useful in connection with two conductor or metallic circuit telephone lines, wherein it enables the earth or return connection at the substa- 55 tion for the operation of the register sele ting mechanto be dispensed with, my invention is also appliloble to single conductor or so called groundcd" nos, and. in tact. provides it particularly convenient .l nethod of securing automatic selective registration in V1! is also obvious that my invention may be practibed and its advantagmus icaturesrcalizcd in cmbodimcnts employing other than the specific mech anism provided in the present instance for reducing or controlling the current; flow in the mctalilic circuit of the line and for selectively responding to the sameto govern the asscciation oi the registers with the line; and it thcreioze is not to beconsidcrcd as being limited to the particular arrangement disclosed.

1. The combination with n telepltondllue extending in two limbs from a. plurnllty of substations to a central otllce, of means thereat for muklug eonnectlon with said llne, a connection register associated with said line at the central ollice, electrically nctuuted'mccuanism tor bringing said register into operative relation with the line, an actuating circuit for said mechanism adapted to be complated at said substations in the act of taking the tele phone for use. and controlling means in a non-grounded bridge between the limbs of the linr at one of sold substations adapted to prevent the operation ot snld mechanism when the telephone ls taken for use at said substation.

.2. The combination with u telephone line extending in two llr'nbs from two substations to a central ofiice, of a bridge of the line at each substation and a telephone switch for controlling the some. a connection register associated with thejine at the central office, electrically actuated mechanism for bringing said regi ter into operarive relation with the line, said mechanism being controlled in sold substation telephone switches, and means included in the bridge of the line at one of said substarlons adapted to prevent tl e'uctuatiou of sold mechanism when the switch at said substation is closed.

3. The comblnatloa with ll telephone line extending in two limbs from two substations to a central cities, or a non-grounded bridge at each substation closed in the use of the telephone thereat, u counectlon reglster assoclnted wltlr the line at the central attice, and normally in my eratlve relation therewltb, an electrleally actuated mechanism adapted to render snid reglstcr inoperative, an actusting clreult [or sald'mechnnlsm closed in said brldges of the line at the substations, and means included In the bridge at one of said subs ations adapted to prevent the actuation oi. sald mechanism when the brldge at said sule station is closed.

4. The cnmblnatlon wllb a telephone llne extendlng from two snltstntldns to aconnection terminal at a central otllce. of a bridge 0! the line at each substation contalnln the telephone apparatus and controlled by the telephone switch, means for making connectlon with the line at the central otilceconncctlon terminal, a. connection register associated with the line at the central olfice, means for operating the connection register associated with the aforesaid connecting means, electrically serrated mechanism adapted to render sold connectlun' register responsive or lrresponslve to the aforesaid operutlng means depending upon the actuated or non-actuated condltlon or said mechanism, on actuating circult for said mechanism adapted tube completed In. the atorrsald bridges of the line at the sirbstatlons,-and a device luterposed in the bridge of tliellne at one of said substntlons adapted to prevent the actuation of sold mechanism when said bridge ls closed. *1

5. The combination wlth a telephonellne cxtcr'nllng from a plurality of substations to n connectlomtcrmlnal at a central oilice, a bridge of the line including the telerhone apparatus and controlled in the telephone switch at each of sold substations, menus for making connection with thellne at the central otbce tcrmlnnl, connection register normally nperatlvcly associated with the connection terminal of the line at the central oflice. means (or actuating said register lssocbited with mild connecting means, electrically actuated mechanism ndapte'd said connection register lnopemtlve. said mcclullllslll bein adapted to respond only to a. predetermined current flowthcretbrough. an 1mm; clrcult for slid mechanism adapted to he completed in the aforesaid bridges of the line at the substations thereof. a high resistance Enter: posed in the bridge at one of the substations adapted to reduce the current flow'below the prcdelermlned amount to prevent the actuatlon'ot said mechanism and thereby maintain the munectlou'reglstcr in 'au operatlre condition,

I may at said mutation adapted to short-clrcult llld to render substation completed in taking the telephone for use,

electrically actuated connection register mechanism associated with the line at the central uficc, said mechanism being adapted to respond selectively in accordance w th the quantity of current flow in the line, a device inter- -posed in the bridge of the line at one oi said substations adapted to alter the current flow in the line to control the operation of said selective mechanism, an electrically actuated switch at said substation adapted to neutralize the aforesaid interposed device. and means nmde operative in completing connection with the line at the central 0t lice adapted in effect the actuation oi. said neutralizing switch.

7. The combination with a. telephone line extending from a plurality of substations to :1 connection terminal at a central ofllce, of means for tr-aktng connection with the line at said terminal, a bridge of the line at each substation including the telephone appcratus and controlled in the te ephone switch, electrically operated connection reglster mechanlsm associated with the line at the central oflice. said mechanism being adapted for selective actuation the selective response of said mechanism depending upon the quantity of current flowing in the line, a resistance interposed in the bridge of the line at one of said substations adapted to alter the currenLllow in the line whcn the bridge is closed to control said selective mechanism, a relay adapted when actuated to neutralize said resistance, and means made operative in the act of completing connection with the line at. the central other adapted to actuate said relay.

8. The combination with a telephone line extending from a plurality of substations to a central otfice. of m ans for making connection with the line at the central ofllcc, connection rcgisters associated with the line at the central ctlico, one for cur-ll of said sub tations, electrica ly actuated mechanism adapted to select and ope-mtivciy associate with the line one or another oi said connection registers, a device at one of said substations adapted to control the actuation of said selcctlng mechanism, neutral lziug means for said device, an electrically actuated switch adapted to-disconnect the aforesaid selecting mechanism from the line, and means made operative in the act of making connection with the line for actuating said neu trnllzing means and said electrical];' actuated switch. whereby the aforesaid device at the substation is rendered inert and said sclectlug mechanism is disconnected from the line.

ii. The combination with a telephone line extending trom a plurality of substations to a connection terminal at a central ofiicc. of means for making connection with the line at said terminal, a bridge at each or said substa ions including the telephone apparatus and controlled by the telephone switch, a device included in the bridge at one of the substations adapted to modify the current flowing in the line, electrically nclunted mechanism connected with the line at the central c lco selectively rcs muslvc to the quantity of current ilow In the line, a plurallly at connection registcni at the central oiilce, onc

for each of said-substations, niluptcd to be selected and.

opcruiivcly associated with the line by said selccliu: mechanism, and mcuus made operative in the act of making connection adapted to neutralize said mmilfying device in the substation bridge.

1b. The combination with a telephone line extending: from a plurality of substations to a central oifice, of a bridge of the line at each oi sold substations including the tclcpbmuapparatus and controlled in the tclcphonc switch. a resistance interposed in said Elrldgc. arnlarlm-i relay having a winding iutenlosod in said bridge, a short circuit of said resistance adapted to be closed in contacts of said relay when thc relay is actuated, a connection regixlcr associated witl' the line at the central ofiic'e. cloctrically actuated mechanism sclcctivcly responsive to the uantity ot current flow in the llne sald mechanism being adapted to control the operative relation of said register with the line. means for making connection with Lhe line at the central otiicc, and menus made operative in the act or making connection adapted to bring about a reversal oi current tiow in the line to actuate said polarized relay at the substation.

11. The comblnaiinnwith a telephone line extending to 2'. connection terminal at a centrai oiiice, of two connection rczisiers associated with the line at the central otlice, mechanism adapted to operatin'ely connect said connection registers with the line alternatively. an electro-mngnct connected together with a source of current in the circuit 01 the line, and being responsive only to a predetermined flow of current. in the line, line signal apparatus connected with the line and adapted to respond to'; less current ilow therein than that 10 which said register-{controlling mech anism is adapted to respond. and means associated with said telephone line adopted to determine the flow of current therein to operate both said register controlling mugnet and said line signal apparatus. or said line signal apparatus alone, whereby the operative relation of said conncctions registers with the line is controlled.

1;. The combination with a. telephone line extending from a plurality of substations to a central oilice, of two connection registers and a line signal associated with the line at the central omce, adapted alternatively to opcratively associate said connec tion registers with the line. electrically actuated mechan ism adapted to effect the operation of said line signal, an actuating circuit for said connection register controlling and signal operating mechanism adapted to be completed in the use of the telephone at any one said substations, said signal operating mechanism being responsive to a smaller flow oi current in the line than that to which said register controlling mechanism is responsive. and means at one of said substations for reducing the current flow in the line to a quantity sulliclent to operate said signal controlling mechanism without operating said register controlling mechanism.

13. The combination with a telephone line extending to a connection terminal at a central oflice, of two connection registers and a line signal associated with the line at the c ntrul oifice, elcctrically actuated mechanism adapted alternatively to bring said connection registers into operolive relation with said connection terminal, means for actuating said registers made operative in completing conncctlon with the line at the terminal thereof. electrically actuated mechanism for operating Bald line signal, said signal actuating mechanism and the aforesaid register con trolling mechanism bclng connected with the line and adopted to respond to current llow therein, sfiid signal actuating mechanism being adapted to respond to a small r current flow in the line than that to which the register controlling mechanism is adapted to respond, means connected with the line for determining a current flow therein sutficicnl to operate both mechanisms, and other means associated with the line for determinlnga current flow suiliclent to operate the signal controlling mechanism but lnsutficlent to operate the register controlling mechanism.

14. The combination with a telephone line extending from two substations to a central otlice,"ot a. connection register and a. line signal associated with the line at the central otilce. mechanism adapted to contr l the operative relation of said connection register with the line, electrically actuated mechanism adapted to control the operaelectrlcally actuated mechanism' tlon of said line signal. said register controlling and said signal controlling mechanlsmshaving their circuits connected with the llnc and being adapted to respond to currcnt flow therein. said signal controlling mechanism heiog arrangcd to respond to a smaller current, than that to which lb.- rogistcr controlling mechanism is arranged to rcspoud. menus associated with the line adapted to deicrminc a current flow suliiclcnt to actuate both mechan' isms. and other moons assiwiatod with the line adapted to determine a current iinw sulliclcnl'. to operate the signal controlling mechanism but lnsulliclcm to operate the re st -r controlling mechanism.

1.1. The combination with a telephonedine cxlendlng in two limbs from two substations to a connection terminal at a central oiiicc, or two connection registers, one {or each for of said suhstalions. electrically actuated mechanism for operativcly assriclatin; either of said registers with said terminal. and means in a nmrgroundcd bridge oi? sa d line at one of the substations for controlling the operation 5 of said mechanism to place in operative relation with the line the particular registe" associated with said substation. iii. The combination with a tciephnne line extending from two substations to u conncction terminal at a central oiiice. of two connection rt-g'isters at the central otiice, onc

-:tclt of said substations. one of said connection register. b ing normally in opcr tire relation with said conncctiou terminal. ciccu'icaily actuated mechanism adapted to rcuder said last mcutioncd i'tu'il ltl' inoperative and bring the other rcgistcr into 0], alive rclatiou with said terminal. and cunlroilin: means in a non-grounded hridLe of the line at one oi said substations adapted to control the operation of said electrically acluatcd nn-chanistn.

17. The combination with a telephone line extending in two limbs t'rom two substations to a c ntral ntlice. oi

means for cstahlishlng connection with the line at the our tral otlice. two connection regist rs at the ccutraT oflice, one for each of said substations. one of said conncction registers being normally opcratlvcbr associated with the line. electrically actuated uierhanism for remit-rim; inoperutlre said connection register and operatirely associating the other register with the line and controlliu! means in a nonrronnded bridge bctwccn the two limbs of the line at one of said substations for determining.' thc operation of said eh tr -all actuated mechanism. to sclect and op- '30 cratlrely associate with the line the particular register corresponding to skid substation.

18. The combination with a telephone line extendiug in two limi s from a plurality (if-substations to n cexytral o[ ticet of means thereat for making connection with said line. a connection register associated with said line at the central otiice. electrically actuated mechanism for controlling the operative relation of said register with the line and means in a non-grounded bridgibetween the limbs of the line at one of said substations adapted to con- 40 trol the operation of said electrically actuated mechanism.

19; The combination with a telephone line extending in two limhs from a plurality of substations to a central 0ttice, of means thereat for making connection with said line, a connection re tcr associated with said line at the central otlice, electrically actuated mechanism for bringing said register into operative relation with the line, contrnllln: means in n nun-h't-tnulcd bridge between the limbs of the line at one a! said substations adapted to determine the operation of said electrically actuated mechanism and actuating means for said conncction register opcratively ister at the central otlicc. a relay adapted to he opertitel upon a predetermined iiow of current thcrethrough to opcrativcly associate said connection register with the line, the wiudim, of s id relay lacing included with a source 0! current in the circuit of said line. means at one of said substations made operative upon taking the telephone for use for producing' in the circuit the predetermined current for actuating said rainy and opcrativeiy connecting said c nnection register with the line, and means at the other station made opcrativc in taking the telephone for use adapted to pct-vent the pct-determined current tiow through said relay.

21. Th combination with a telephone line extending from two substations to a central otiice, of means thereat for making connection with said line, a connection registcr at the central otiice ormally operatlvely associated with said line. a relay havlnswitch contacts atio'pted upon the actuation of said rt 1y to destroy the operative relation of said rvzistcr with thc line. the winding of said rcla being: included with a source of current in the circnit of the line. said run being adapted tn requlre a pro dctr-rtnint-d current flow for its actuation. mean. made operative upon ittltltlf. the telephoto for use at 0 ie of said uhslatiuhs tor producing in thc line the predetermined cnrrcnl How for said rcla and means made operative in takin: the telephone for l. V at the other substation for lilillitl: the current tlow in the line to a quantity less than sntiicirnt for operation of sa d relay.

-J. The combination with a telephone line extending from a plurality of substations to a connection terminal at a central otiice. of means tin-rent for making: connection with said line, a connection register associated with said line at the central ofiice. a relay having switch contacts adapted to bring said connection register into operative relation with the connection terminal of said line. said relay being included. together with a source of current n the circuit of said line and being adapted to require a predetermined current llow for its operation. bridges of the line at said substations controlled in the telephone switches thereat. a device included in the bridge at one oi said substations for reducing the current: llow below the predetel-rained amount so that. the aforesaid rein, will not he op'u'ntcd when the telephone at that station is taken for use. the current tiow through the bridge at the other substation being adapted to be sutficlent to actuate said relay, and electrically actuated mechanism at the first mentioned substation responsive to the aforesaid connecting means at the central (mice, and adapted to render inoperative said current reducing: device.

, JAMES L. McQUARRlE.

Witnesses: I

ltor '1. ALLOWAY, E. l-.- iii-tannins. 

